Blazer Forum - Chevy Blazer Forums - A/C Compressor Won't Engage

Quote:

Originally Posted by christine_208 (Post 709214)

So does replacing the pressure switches on the AC system require removal of the refrigerant? I have a 1999 GM service manual and it makes no note of doing that for the High-Pressure Cut-Out Switch nor for the Pressure Cycling Switch. However for other AC service, such a hose replacement the manual will (not surprisingly) mention recovering all of the refrigerant.

Well there isn’t a schrader valve on the compressor. The high pressure switch is installed with an o-ring directly into the socket on back of the compressor and secured with a snap ring. In the socket, there is a hole on the compressor which I assume Freon/oil flows by so that the high pressure switch can read the pressures. When you remove the high pressure switch on a working system, there is oil in that socket so I assume the system is exposed/opened if that switch is removed. I took my Freon out before I took off the compressor so I am not 100% sure.